Engineered truss systems Flashcards
Which truss design is prone to horizontal deflection as well as to vertical deflection?
Scissor truss
Where can the instructions for the proper lamination of a girder truss be found?
Included with the truss documentation
Loads can be divided into two groups. What are they?
Live loads
Dead loads
Which type of a load is a layer of roofing plywood attached to the trusses?
Dead load
Which type of load is a pile of roofing plywood placed on the roof trusses prior to installation?
Live loads
What are the two basic forces that continually act on a truss?
Tension
Compression
On what does the compressive strength of a member depend?
Depends on the unsupported length
Against what type of forces is wood the weakest?
Tension forces that are perpendicular to the grain
What is the best position in which to keep a truss while it is being lifted and moved?
Vertically
What is the function of top chord bracing?
Transfer loads, keeps trusses plumb and maintain proper O.C. spacing
What is the maximum distance recommended between runs of bottom chord bracing?
10 feet
Where is diagonal bracing required on the bottom chord?
Either end of building and repeated at a maximum of 6m (20 feet)
What are the three main functions of permanent bracing in a trussed roof system?
- Decrease the unsupported length of compressive members
- Increase stability of the truss system
- Assist the truss system with load transfer
What are the three main types of permanent bracing?
- Top chord bracing
- Bottom chord bracing
- Bracing of the web member plane
How is lateral movement prevented if purlins are installed as opposed to continuous sheathing?
Diagonal bracing should be installed on the underside of the top chords
